Sealed slide plates for rotary internal combustion engine

ABSTRACT

A rotary internal combustion engine including a stator having a circular chamber within which is coaxially disposed a shaft supporting an off-center circular rotor, the diameter of the rotor being such that the distance between the center of the shaft and the zenith on the rotor periphery is substantially equal to the radius of the chamber whereas the distance between the center of the shaft and the nadir on the periphery is substantially equal to half this radius. Extending into the chamber are slide plates which are urged into continuous contact with the rotor surface to divide the chamber into operating zones of varying volume into which fuel charges are admitted for compression and ignition to produce gas expansion creating torque forces, the spent gases being exhausted from the zones. The slide plates are fully sealed to prevent gas leakage and are hydraulically interlinked whereby the plates engage the rotor with a constant pressure.

United States Patent Abbey SEALED SLIDE PLATES FOR ROTARY INTERNAL COMBUSTION ENGINE 21 1 App]. No.2 452,966

Related US. Application Data Continuation-impart of Ser. No. 318,664, Dec. 26, 1972, Pat. No. 3,809,024.

Dec. 2, 1975 [57] ABSTRACT A rotary internal combustion engine including a stator having a circular chamber within which is eoaxially disposed a shaft supporting an off-center circular rotor, the diameter of the rotor being such that the distance between the center of the shaft and the zenith on the rotor periphery is substantially equal to the radius of the chamber whereas the distance between the [52] us 418/61 R; 418/139; 418/249 center of the shaft and the nadir on the periphery is [51] Int. Cl. F02B 53/00 Substantially equal to h lf i radius Extending i [58] Field of Search 123/845; 418/61 the chamber are slide plates which are urged into con- 418/139 249 tinuous contact with the rotor surface to divide the chamber into operating zones of varying volume into [56] References C'ted which fuel charges are admitted for compression and UNITED STATES PATENTS ignition to produce gas expansion creating torque 767,442 8/1904 Robinson 418/248 forces the Spent gases being exhausted from the 902,762 11/1908 Risley 418/139 X zones. The slide plates are fully sealed to prevent gas 1,158,467 11/1915 Evans 418/61 R leakage and are hydraulically interlinked whereby the 2,005,141 6/1935 Gutzwiller 418/249 X lat ngag th rotor with a constant pressure, 3,244,157 4/1966 Tanfernta et al. 418/139 X 9 Claims, 19 Drawing Figures EYMqus? I /IYT Z1 1746f I Qfmuar P lq l. 1m .1, g 1 Z Q" D P3 2 (A D P4 26 Q:

as 30 Exmasr 11 51;... 5 a lmzr .|7'1. g 4 %;2 fi Q 7 U.S. Patant Dec. 2, 1975 Sheet 1 0f 6 EVHAUST US. atent Dec. 2, 1975 Sheet 2 of6 3,923,431

US. Patent Dec. 2, 1975 Sheet 3 of6 3,923,431

US. Patent Dec. 2, 1975 Sheet 4 of6 3,923,431

Sheet 5 of 6 3,923,431

US. Patent Dec. 2, 1975 MOM] 111m. 0

US. Patent Dec. 2, 1975 Sheet 6 0f 6 SEALED SLIDE PLATES FOR ROTARY INTERNAL COMBUSTION ENGINE RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 318,664 filed Dec. 26, 1972, and now U.S. Pat. No. 3,809,024.

' BACKGROUND OF THE INVENTION This invention relates generally to rotary internal combustion engines, and more particularly to a rotary engine wherein an eccentrically-mounted rotor sweeps cyclically through a circular stator chamber and cooperates with slider plates which continuously engage the rotor surface to define operating zones to carry out a four-stroke or two-stroke internal combustion action that directly generates a rotational force.

In a standard internal combustion gasoline engine of the reciprocating-piston type, a combustible mixture is compressed in a cylinder and ignited. The gases which are produced in the cylinder by the combustion of the gasoline-air mixture, expand and thrust the piston downwards. Acting through a connecting rod, the piston imparts a rotary motion to the crankshaft. The spent burned gases must then be removed from the cylinder and replaced by a fresh fuel charge, so that a new cycle can begin. The energy for effecting this change in the contents of the cylinder, is supplied by a flywheel which stores some of the released energy.

A distinction must be drawn between four-stroke and two-stroke operation in an internal combustion engine. To carry out a full cycle of operations, including changing the contents of the cylinder and effecting combustion, the four-stroke engine requires four strokes of the piston, whereas the two-stroke engine entails only two piston strokes.

The present invention makes use of a continuously rotating rotor supported eccentrically on an output shaft coaxially mounted within a circular stator cham- .ber to directly produce a rotational force. This rotary engine goes through the equivalent of a four-stroke or two-stroke action, but since no piston is involved, there is no reversal of direction, as in a piston-engine, where the piston must come to a complete halt before changing direction.

In the above-identified copending application Ser. No. 318,664, there is disclosed a rotary engine capable of operating on the four-stroke or two-stroke principle without, however, at any time reversing direction, to convert the thrust of the expanding gases directly into rotary motion. The entire disclosure of said copending application is incorporated herein by reference.

The above-identified copending application discloses a rotary internal combustion engine wherein a circular rotor is eccentrically mounted on an output shaft disposed coaxially within a circular chamber, the diameter of the rotor being such that the distance between the shaft center and the zenith point on the rotor periphery is substantially equal to the radius of the chamber, whereas the distance between the shaft center and the nadir point on the periphery is substantially equal to half this radius, whereby as the rotor sweeps the chamber the zenith travels in a circular scan path without actually making contact with the wall of the chamber.

In the four-stroke embodiment of the engine, the chamber is divided into four operating zones by four slide plates arranged in quadrature and extending radially into the chamber, the plates being urged into continuous engagement with the rotor surface. Each zone operates with a combustion cavity containing the gap electrodes of a sparkplug as well as intake and exhaust valves, whereby in the course of two full revolutions of the rotor, a fuel mixture is induced into the zone, compressed therein, ignited to undergo power expansion generating a thrust force on the rotor, after which the spent gases are exhausted.

In the four-stroke arrangement, ignition in the four zones is effected in a timed sequence wherein ignition takes place in the course of the first revolution in one pair of opposing zones, and in the course of the second revolution in the other pair of opposing zones, whereby four power pulses'are generated at quadrature positions during the two revolutions to complete a full operating cycle imparting a high torque to the shaft and giving rise to a smooth-running, substantially uniform rotary output motion.

In the two-stroke embodiment of this engine, one pair of opposing zones cooperates with combustion cavities containing the gap electrodes of two sparkplugs, there being a lateral exhaust port in each of these zones whose opening and closing is determined by the position of the rotor relative thereto. The other pair of opposing zones operates with respective lateral fuel supply ports whose openings and closings are determined by the position of the rotor relative thereto.

In this two-stroke arrangement, ignition takes place alternately one-hundred eighty degrees apart in the course of each revolution of the rotor, the air-fuel mixture taken into a zone which includes a supply port being compressed in the next zone and ignited therein to produce power expansion, the spent gases being discharged through the exhaust port.

As noted in the copending application it is vital for efficient operation of the engine, whether of the two stroke or four stroke type, that the slide plates be effectively sealed to avoid the escape of 'gas and the resultant reduction in gas pressure. llnasmuch as these slide plates operate within guides in the stator, and the ends of the plates engage the surface of the rotor, many points of possible leakage exist, for in order for the plates to slide, clearances are necessary. The present invention is directed to slide plate structures which are fully sealed to avoid gas leakage in any direction, and yet are free to reciprocate.

In the slide plate arrangement disclosed in the copending application, the plates are urged by springs toward the surface of the eccentrically-mounted rotor and as the rotor turns, each plate moves from a fullyretracted position in which it is withdrawn from the operating chamber to a fully-extended position in which it has its maximum extension in the chamber. Because the plate excursion is large, the repetition rate of this action is very high and the springs are subject to fatigue and failure. The present invention deals with a hydraulic system for operating the plates.

SUMMARY OF THE INVENTION In view of the foregoing, it is the main object of this invention to provide an improved rotary engine wherein a circular rotor eccentrically mounted on an output shaft coaxially positioned within a circular stator chamber, is caused by forces produced by internal combustion to rotate with substantially uniform motion.

More particularly it is an object of the invention to provide a rotary engine of the above-type in which the stator chamber is divided by slide plates engaging the rotor surface into operating zones, the slide plates being tracked and fully sealed to avoid leakage from the zones, thereby to optimize the efficiency of the engine.

Also an object of this invention is to provide a hydraulic system linking the slide plates of the rotary engine, the link acting to maintain each plate into engagement with the surface of the rotor with a constant pressure.

Briefly stated, in a rotary internal combustion engine in accordance with the invention, a shaft supporting an off-center circular rotor is coaxially mounted within the circular chamber of a stator. Extending into the chamber are slide plates which are tracked in guide slots formed in the internal side walls of the stator, the inner ends of the slide plates being urged into continuous contact with the rotor surface and being caused to reciprocate as the rotor turns, the plates dividing the chamber into operating zones of varying volume into which fuel charges are admitted for compression and ignition to produce gas expansion creating torque forces, the spent gases being exhausted from the zones.

In order to maintain the inner ends of the slide plates in engagement with the rotor surface with a constant pressure, the outer end of each plate is operatively coupled to a piston movable within a cylinder of a pneumatic actuator which is linked to the cylinders of identical pneumatic actuators whose pistons are operatively coupled to the other slide plates whereby retracting plates cause their associated pistons to undergo a return stroke to produce in their related cylinders an air pressure which is transmitted to the other cylinders to cause the pistons therein to undergo an advance stroke, acting to press their associated slide plates against the rotor surface. Inasmuch as equal phase displacement exists between the slide plates, the pump actions and the resultant air pressure are likewise displaced so that the hydraulic linkage acts to maintain a constant plateto-rotor pressure.

Each slide plate is provided with a pair of legs which straddle the peripheral edges of the rotor, the rotor surface engaging the bearing surface of a cross piece extending between the legs. The legs are provided with spring-biased plugs which are urged against the edges of the rotor, the legs terminating in feet encircled with rings seals whereby leakage through the clearances at the rotor edges is prevented. The edges on the main body of the slide plate are equipped with spring biased sealing bars and the sides of the main body are encircled by sealing rings whereby leakage through the sides and edge clearances of the slide plate is avoided.

OUTLINE OF THE DRAWINGS For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view of a four-stroke rotary engine in accordance with the invention.

FIG. 2 is a transverse section taken in the plane indicated by line 2-2 in FIG. 1;

FIG. 3 is a perspective view of one of the slide plates of the engine shown in relationship to the rotor;

FIG. 4 is an elevational view, partly in section of the slide plate shown in FIG. 3;

FIG. 5 is a section taken in the plane indicated by line 5-5 in FIG. 4;

FIG. 6 is an end view of the slide plate shown in FIG.

FIG. 7 is a section taken in the plane indicated by line 77 in FIG. 4;

FIG. 8 is a section taken in the plane indicated by line 88 in FIG. 4;

FIG. 9 is a detail of the structure shown in FIG. 8;

FIG. 10 is the same as FIG. 4 except that all sealing elements and their associated springs are removed from the slide plate;

FIG. 11 is an end view of the slide plate shown in FIG. 10;

FIG. 12 is a perspective of a sealing plug included in the slide plate;

FIG. 13 is a perspective of a sealing bar included in the slide plate;

FIG. 14 is a perspective of a split sealing ring included in the slide plate;

FIG. 15 is an elevational view, partly in section, of another embodiment of a slide plate in accordance with the invention; and

FIG. 16 is a section taken in the plane indicated by line l6l6 in FIG. 15;

FIG. 16A is an alternative form of sealing ring for the slide plate shown in FIG. 16;

FIG. 17 is a partial end view of the slide plate shown in FIG. 15; and

FIG. 18 shows one of the ring seals included in FIG. 15.

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there is shown a preferred embodiment of a four-stroke rotary engine which includes hydraulically-operable, fully-sealed slide plates in accordance with the invention. The main components of the engine are a rotor, generally designated by numeral 10, and a stator, generally designated by numeral 11. While the invention is illustrated in conjunction with a four-stroke rotary engine, it is also applicable to the two stroke and all other-rotary engine forms disclosed in the above-noted copending application.

Rotor 10 has a perfectly circular configuration, and is directly mounted off-center on an output shaft 12, coaxially supported within the circular chamber of stator l l. The diameter of the rotor is preferably such that the distance D between the center X of shaft 12 and the zero degree or zenith point Z on the periphery of the rotor, is substantially equal to the radius of the chamber, whereas the distance D, between shaft center and the l-degree or nadir point N on the rotor periphery, is substantially equal to one-half the radius of the chamber.

There is minimal clearance between zenith point A on the rotor and the wall of the stator chamber. Though there is no point of contact between the rotor and stat'or in the course of revolution, the minimal clearance therebetween does not constitute a leakage or loss path for it is part of the chamber and its clearance volume.

The zenith of the rotor sweeps through a circular scanning path that is concentric with the wall of the statoward the chamber wall to compress a fuel mixture in the associated chamber zone to an extent determined by the clearance volume afforded by the engine design.

In this context, the wall of the chamber effectively acts as a cylinder head (again using the piston-cylinder analogy) while the side plates of the chamber function as the cylinder wall. However though the present rotary engine is in some respects analogous to a reciprocating piston engine, it must always be borne in mind that the operating strokes in the present engine are carried out in the course of rotor revolution always in the same direction without any reversal or deceleration.

The chamber of stator 11 is divided into four distinct quadrature zones A, B, C and D, by radially-extensible slide plates P P P and P each of which is biased in a manner to be later described to urge the free end of the plate to engage the surface of rotor and maintain continuous contact therewith with a substantially constant pressure. Formed in the stator and communicating with zone A, is a combustion cavity C within which are disposed the gap electrodes 16 ofa sparkplug 13.

Disposed on either side of sparkplug 13 are two valves, one of which functions as an intake valve 14 leading to a fuel inlet port 15. The second valve functions as an exhaust valve 17 leading to an exhaust port 18. The valve and sparkplug structures are similar to those in a conventional piston engine.

Similarly, a combustion chamber C communicates with zone B, within which are disposed the gap electrodes of a sparkplug 19. Associated with this cavity are an intake valve 20 leading to fuel inlet port 21, and an exhaust valve 22 leading to exhaust port 23. A combustion cavity C communicates with zone C, within which are disposed the gap electrodes of a sparkplug 28. Associated with this cavity are intake valve 24 leading to fuel inlet port 25, and exhaust valve 26 leading to exhaust port 27.

Zone D communicates with combustion cavity C within which are disposed the gap electrodes of sparkplug 29, and associated with this cavity are intake valve 30 leading to inlet port 31, and exhaust valve 32 leading to exhaust port 33.

We shall at this point not further consider the mechanical details of the engine, including the means by which the components thereof are sealed to prevent leakage from the four zones, nor the manner in which the valves are manipulated in the course of an operating cycle, for these will be analyzed after the basic operating principles are explained and clearly understood. (A more detailed explanation may be found in the above-noted copending application).

It will be seen that in the course of a single 360 degree, clockwise revolution of the rotor from the zenith position Z shown in FIG. 1, the zenith of the rotor will initially engage slide plate P to force this plate fully out of the stator chamber, and that as this zenith Z scans the wall, it will successively engage slide plates P P P and back again to plate P forcing each plate in turn into its fully retracted position.

As the zenith Z moves clockwise away from each plate, the plate, which always engages the periphery of the rotor, proceeds to move radially into the chamber until it reaches the nadir N on the rotor periphery, at which point the plate has its maximum extension from the stator wall, after which the plate is progressively pushed out of the chamber until it again reaches rotor zenith Z. Hence the zone established between any two slide plates has a changing volume determined at any instant by the relative degree to which the related plates are extended into the chamber.

Each zone has its minimum volume when zenith Z of rotor 10 is exactly midway between the pair of associated plates defining the zone. Maximum volume is attained when nadir N is at this midway position. Between the maximum and minimum levels, the volume undergoes changes as the rotor turns. This change in volume is known in engine parlance as the displacement.

When a mixture compressed in an operating zone is ignited, the expanding gases produce a torque force just as soon as the center of gas pressure on the arced surface of the rotor passes the point of alignment with the shaft center X. This point of alignment in piston engines is referred to as top dead center.

In a four-stroke rotary engine in accordance with the invention, each quadrature zone of the stator chamber through which the rotor sweeps, undergoes fuel induction, compression, ignition, power expansion, and exhaust, once every two revolutions of the rotor.

Thus the first revolution of the rotor is accompanied by two successive power pulses, and the second revolution by two successive power pulses which are in staggered time relation to the first two pulses, thereby avoiding deceleration of the rotor and producing a substantially uniform torque. As in a four-stroke fourcylinder piston engines, the firing order in the present invention is Zones A, C, D, B equivalent to cylinders l, 3, 4, 2 in a conventional four-cylinder engine.

It is to be understood that the invention is also applicable to a rotary engine operating on diesel principles, for diesel engines are also designed to operate on the four-stroke or two-stroke principle, just like gasoline engines. The combustion process in the diesel engine differs from that in a gasoline engine in that instead of drawing in a gasoline-air-mixture, air alone is drawn and compressed to a relatively high ratio, as a result of which the air is heated to a temperature in excess of 700 C. Only then is diesel fuel injection into a chamber. Because of the prevailing high temperature, the fuel ignites spontaneously. The injection nozzle is designed so that its spray pervades all the air in the combustion chamber. Sealing: In connection with FIG. 2, we shall now consider the manner in which the rotary engine is effectively sealed and the means by which wear is reduced. As pointed out previously, there is no actual point of contact between the periphery of the rotor and the inner surface of the stator chamber. The operating zones are defined by slide plates P to P which continuously engage the periphery of the rotor, these points of engagement representing the only points of wear. But wear at these points is minimized in that the periphery of the rotor does not undergo the same rotational motion as the rotor body, as will be; explained hereinafter.

Shaft 12 of rotor 10 is supported on either end by sleeve bearings 34 and 35 fitted into the end plates 11A and 11B of the stator structure. Rotor 10 which is eccentrically mounted on shaft 12, is provided with a peripheral collar 10A whose width is such that it extends at either end beyond the edges of the rotor body. Peripheral collar 10A is freely mounted on rotor 10 and is capable of independent rotation thereon. Hence as eccentric rotor 10 turns about shaft 12, the peripheral collar, which is subjected to radial pressure by the slide plates P to P is carried through the rotor scanning circle but its rotation is resisted by the plates which in the course of a rotor revolution move in and out of the stator chamber and continuously engage the collar. As the rotor turns eccentrically on shaft 12, the peripheral collar thereon undergoes epicyclic motion in which sliding motion between the collar and plates is minimized although some degree of collar rotation will be experienced.

It is to be noted that oil lubrication passages (not shown) are provided in shaft 12 which lead to the interface of the rotor body and peripheral collar as well as to bearings 34 and 35. It is to be understood however that the invention is not limited to this collar arrangement and that in practice, particularly with low-cost motors, the peripheral collar may be omitted, in which event the plates bear directly against the rotor body.

Sealing of the rotor surface from escape of gases in the cavity and from the entry of lubricating oil into the cavity is effected by means of rings 36 and 37 each having a rectangular cross section. The rings are received within annular grooves formed in the left end of the peripheral collar A and are urged by suitable springs against the feet of the slide plates in the manner to be later described, the rings being in sliding contact therewith. A similar set of rings is provided for the right end of the collar.

Each slide plate, as exemplified by slide plate P in FIGS. 3, 4 and 10, is formed by a basic rectangular block which is machined to define a pair of feet F,, and F adapted to straddle the peripheral collar 10A of the rotor. Extending along the crotch between the feet is a bearing rod 38 formed on high-strength, anti-friction material, rod 38 engaging the surface of collar 10A thereby effectively sealing the cavities from one another at the rotor surface.

The extremities of bearing rod 38 are received in concave sockets formed in sealing plugs 39a and 39b accommodated within suitably contoured slots formed in feet Fa and Fb respectively. The plugs 39a and 39b are pressed against the edges of rotor collar 10A by springs 40a and 40b as shown in FIGS. 4 and 12.

Received within appropriately-shaped slots formed below sealing plugs 39a and 39b in feet Fa and Fb are resilient O-rings 41a and 41b which are surrounded by sealing rings 42a and 42b respectively. These sealing rings have a rectangular frame formation and are each formed by four L-shaped metal pieces which are assembled on the associated foot. The O-rings act to press the sealing rings against the related edges of the rotor collar 10A and the three sides of the rectangular stator slots. Alternatively, the sealing rings may each be composed of two L-shaped pieces 43x and 43y, as shown in FIG. 14, whose extremities have a step formation whereby the pieces mesh together on the associated foot of the slide plate.

Thus the seal plugs and the sealing rings which engage the edges of the rotor collar act to prevent leakage at the junction of the feet of the slide plate and the rotor collar. To prevent leakage through the guides for slide plates, each plate as shown in FIGS. 3 and 4 is provided by a pair of body sealing rings 43 and 44, each of which may be formed in the manner described in connection with the feet sealing rings 42a and 42b. Sealing ring 43 is disposed in a suitable slot in the body of the slide plate at a position that allows maximum extension but still within the stator wall, whereas sealing ring 44 is adjacent the upper end thereof. to provide dual protection against leakage. These rings are biased outwardly by suitable springs, such as springs 45, 46 and 47 shown in FIG. 7.

The edges of the slide plate are sealed by sealing bars 48a and 48b received in edge slots, the bars being biased outwardly by suitable springs, such as springs 49 and 50 for bar 48a and springs 51 and 52 for bar 48b as shown in FIG. 4. The springs 40 and 41 act simultaneously to bias bars 48a and 48b outwardly while urging plugs 39a and 39b inwardly. At the junction of the sealing bars and the body sealing rings, the bars are notched to accommodate the rings, so that the exposed surfaces of the body sealing rings are coplanar with the exposed surfaces of the bars.

As shown in FIG. 3, the slide plate assembly formed by the plate and its sealing rings may be installed in an appropriately dimensioned groove or slot in the stator of the motor, or the assembly may be contained in a suitable sleeve having a matching rectangular cross section, which sleeve and slide plate assembly is placed in the slot as a unit. The sealing arrangement is such as to protect the rotor and associated slide plate at all possible points of leakage to optimize the generation of mo tive power.

In the slide plate arrangement shown in FIGS. 2 to 14, the corners thereof are squared off, whereas in the functionally equivalent arrangement shown in FIGS. 15 to 18, the corners are rounded. In the latter oval arrangement, the slide plate P r is provided with chamfered edges, the plate being slideable within a similarly rounded sleeve 53. The foot seals 54 which are made of spring metal have a split D formation, the seals being pulled open when being installed on the feet. The body seals 55 and 56 are located adjacent the upper end of the slide plate. The edge sealing bars 57 and 58 are rounded and received in suitable slots in the edges of the plate, springs being provided to bias the seals. The split oval slide plate seal ring R shown in FIG. 16A provides side and end slot sealing for an oval plate in an oval sleeve without the need for springs such as springs 45, 46 and 47.

The hydraulic system In order to maintain the inner ends of the slide plates in firm engagement with the rotor surface with a substantially constant pressure, the outer end of each plate is coupled or shown in FIG. 1 in connection with plate P4, to a piston 60 by means of a freely movable push block 61. Piston 60 reciprocates within an air cylinder 62 mounted on the exterior of the motor stator. The piston 60 is biased by a light helical spring 63 which serves to urge the associated slide plate toward the rotor surface but is inadequate to serve as the sole means for this purpose.

Identical pistons and air cylinder assemblies are associated with the other slide plates P P and P The four air cylinders are interlinked by hydraulic lines 64 and supplied through check valve 65 with a biasing pressure air supply 66 from a suitable compressor. Thus the air cylinder for plate P is linked to that for plate P which in turn is linked to that for plate P which is linked to that for P which is linked to the air cylinder for plate P,, thereby defining a continuous interconnecting loop.

In the course of a full rotor turn, each slide plate moves in and out from its maximum extended to its maximum retracted positions, the four plates reciprocating in phase quadrature. At the instant when plate P, is fully retracted, as shown in FIG. 1, with the rotor turning in the clockwise direction, plate P is half retracted, plate P is fully extended and plate P is half extended.

As a plate moves outwardly toward its fully retracted position, it pushes its associated piston down the air cylinder to create an air pressure which is transmitted by the hydraulic lines to the other cylinders, the transmitter pressure acting on the piston associated with the then inwardly moving plates. The ends of the plates regardless of their direction of movement are at all times in engagement with the rotor, the prevailing air supply pressure acting to maintain this engagement with substantial constant pressure. Because of the compressibility of air, the system is non-rigid, the distributed air pressure in the four cylinders being essentially equal in any position of the quadrature relation of plate move ment.

While there has been shown preferred embodiments of the invention, it will be appreciated that many changes may be made therein without departing from the essential spirit of the invention.

I claim: I

1. In an internal combustion engine, the combination comprising a circular rotor eccentrically supported on a shaft, a stator having a circular chamber, said shaft being coaxially mounted within the circular chamber of said stator, slide plates extending into said chamber and in continuous contact with the rotor surface to divide the chamber into operating zones of varying volume, the slide plates being tracked in guide slots formed in the internal side walls of the stator, each slide plate being constituted by the main body from which extends a pair of legs straddling the peripheral edges of the rotor, and a cross piece extending between the legs and formed of a bearing material engaging the surface of the rotor, the legs terminating in feet encircled with ring seals which are pressed against the related edges of the rotor and the sides of the guide slots, whereby leakage through the clearances at the rotor edges and at the guide slots is prevented.

2. An engine as set forth in claim 1, wherein the legs are provided with spring-biased plugs which are urged against the edges of the rotor.

3. An engine as set forth in claim 3, wherein said plugs are provided with concavities to socket the ends of said cross piece.

4. An engine as set forth in claim 1, wherein the edges of the plate body are equipped with spring-biased sealing bars. i

5. An engine as set forth in claim 1 wherein the sides of the main body are encircled with ring seals.

6. An engine as set forth in claim 1, wherein said sealed plate is housed in a sleeve.

7. An engine as set forth in claim 1, wherein the edges of said plate are rounded.

8. An engine as set forth in claim 1, wherein the slide plates are hydraulically interlinked to maintain the pressure of plates against the rotor substantially constant, said hydraulic linkage including a piston mechanically coupled to each plate, said piston reciprocating within an air cylinder.

9. An engine as set forth in claim 8, wherein said mechanical coupling is effected by a freely movable block interposed between said piston and the upper end of the associated slide plate. 

1. In an internal combustion engine, the combination comprising a circular rotor eccentrically supported on a shaft, a stator having a circular chamber, said shaft being coaxially mounted within the circular chamber of said stator, slide plates extending into said chamber and in continuous contact with the rotor surface to divide the chamber into operating zones of varying volume, the slide plates being tracked in guide slots formed in the internal side walls of the stator, each slide plate being constituted by the main body from which extends a pair of legs straddling the peripheral edges of the rotor, and a cross piece extending between the legs and formed of a bearing material engaging the surface of the rotor, the legs terminating in feet encircled with ring seals which are pressed against the related edges of the rotor and the sides of the guide slots, whereby leakage through the clearances at the rotor edges and at the guide slots is prevented.
 2. An engine as set forth in claim 1, wherein the legs are provided with spring-biased plugs which are urged against the edges of the rotor.
 3. An engine as set forth in claim 3, wherein said plugs are provided with concavities to socket the ends of said cross piece.
 4. An engine as set forth in claim 1, wherein the edges of the plate body are equipped with spring-biased sealing bars.
 5. An engine as set forth in claim 1 wherein the sides of the main body are encircled with ring seals.
 6. An engine as set forth in claim 1, wherein said sealed plate is housed in a sleeve.
 7. An engine as set fortH in claim 1, wherein the edges of said plate are rounded.
 8. An engine as set forth in claim 1, wherein the slide plates are hydraulically interlinked to maintain the pressure of plates against the rotor substantially constant, said hydraulic linkage including a piston mechanically coupled to each plate, said piston reciprocating within an air cylinder.
 9. An engine as set forth in claim 8, wherein said mechanical coupling is effected by a freely movable block interposed between said piston and the upper end of the associated slide plate. 